1. Field of the Invention
This invention relates to an apparatus for applying surgical fasteners and more particularly, to a fastener applying apparatus having an improved fastener cartridge and holder for the retainer portion of two-part surgical fasteners.
2. Background of the Prior Art
In some surgical operations it is necessary to adjoin two hollow body organs alongside each other, with their longitudinal axes positioned generally parallel to each other, and to effect a longitudinal cut through the contacting circumferential walls of the two organs in order to open them to each other. After joining the two organs they essentially constitute a single hollow chamber along the length of the cut. Correspondingly, the circumferential portions of the two adjoining organs on each lateral side of the cut must be sutured by at least one line of "stitches" in order to maintain the integrity of the union.
Instruments for this purpose are known in the art, and are described in U.S. Pat. Nos. 3,079,606, 3,490,675 and 3,499,591. Such instruments are generally referred to as linear cutting staplers and include two elongate fingers which are respectively insertable into each organ from an open end thereof such that the two fingers have the adjoining walls of the adjacent organs therebetween. Further examples of such instruments are disclosed in commonly assigned U.S. Pat. Nos. 4,429,695 and 4,520,817. The disclosures of these two last mentioned patents are incorporated herein by reference.
One of the fingers includes a disposable cartridge carrying a plurality of staples arranged in at least two lateral rows while the other finger includes an anvil for curling the staple legs into hook form upon being driven against the anvil. The stapling operation is effected by a pusher device which travels longitudinally along the cartridge carrying finger extending into one organ. The pusher mechanism acts simultaneously upon the staples at corresponding longitudinal positions in each lateral row, but successively acts upon the staples along the rows. For example, if two laterals rows of staples are provided, each row comprising twenty staples, the pusher means acts upon two staples at a time, one in each row, and successively acts upon each succeeding pair of staples.
Immediately behind the pusher means and laterally positioned between the staple rows is a knife member which severs the facing adjoining walls of the two organs to thereby longitudinally open the two organs to each other between the rows of staples.
Up to the present these devices were limited to applying metal staples. Two-part absorbable fasteners, such as those used in devices described in U.S. Pat. No. 4,665,916, hereby incorporated by reference, have been limited to devices which apply all of the fasteners simultaneously. Indeed, the retainer members of such absorbable fastener devices typically have been constructed as a web of retainers interconnected by flexible or frangible members. See, for example, U.S. Pat. No. 4,589,416. Devices of the type shown in the aforementioned U.S. Pat. Nos. 3,079,606; 3,490,675 and 3,499,591, on the other hand, employ an actuating cam bar which travels substantially perpendicularly to the direction of fastener motion to effect sequential placement of staples.
Up to the present, applying two-part absorbable fasteners with instruments of the type disclosed in U.S. Pat. Nos. 3,079,606; 3,490,675 and 3,499,591 has not been possible due in part to the peculiar difficulties inherent in aligning the separate fasteners and retainers. The present invention relates to an apparatus which successfully combines a system of applying such fasteners sequentially while cutting the tissue and effecting complete closures.